A Mechanistic Theory of Consciousness

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Introduction

The current work is the result of an amateur interest in the philosophy of mind coming into contact with an Internet news aggregator. In my aggregated news I started seeing references to David Chalmer’s now famous phrase: The Hard Problem of Consciousness (TM?), and I couldn’t see what the big deal was. It didn’t seem hard to me at all. Consciousness was something the brain did, and so that meant information processing. I tried to twease out what various writers meant when they used the term “consciousness”, but I never found anything that couldn’t be described as information processing.

Eventually, although it would probably be more accurate to say inevitably, I found one of the internet’s more prolific philosophical presences: Massimo Pigliucci. More specifically, I found his webzine (first, Rationally Speaking, then Scientia Salon, both unfortunately now defunct) which not only produced interesting articles (when they involved consciousness) but also provided a forum for discussion. There was one article in particular that instigated my need to set some people straight. That article was Three and a half thought experiments in philosophy of mind. This article presented the famous Chinese Room as well as the concept of P-zombies (with Mary the color scientist and “What it’s like to be a bat” making up the other 1.5 thought experiments).

A P-zombie (for philosophical zombie) is a creature that looks and acts like a normal human, but is dead inside, i.e., has no experience and no consciousness. In the article Pigliucci rightly concludes that p-zombies are physically impossible. But then in the same article he presents the Chinese Room as something that is physically possible, and can act like (if not look like) a normal human, but is not conscious. This discrepancy gets raised in the comments, and Pigliucci responds, but not in a way that changes anyone’s mind. What stood out to me in the comments was that there were many people saying things that were or were not true, and other people responding with things that were or were not true, but nobody’s comments were changing anyone’s mind. After some consideration I concluded that these people were largely talking past each other. I am not the first to notice that certain words used in these discussions, especially words like consciousness, understanding, and intelligence, are not well defined. I have also noticed that philosophers are not rigorous about specifying the boundaries to which they apply these terms, the Chinese Room being the classic example. Referring to that example, Pigliucci (and Searle) say that nothing in the Room understands Chinese, and the standard opposing response is “the Room as a whole understands Chinese” ( which I believe is called the “systems response”).

In any case, I decided that there were a large number of people whose minds I wanted to change (which is everyone who thinks the problem of consciousness is “hard”), but that in order to do that I would have to be crystal clear in my use of terminology. Given that my premise is “consciousness is information processing”, my first tasks were clear: define information, describe what “processing” could be, and explain the relationship of processing information to consciousness.

Now the standard idea of an information process looks something like this: Input -> [processor] -> Output. But I knew I would have to be extremely rigorous about each facet of such a process, so I explored the internet for help, and I came across what I believe is the perfect framework for this purpose: David Deutsch’s Constructor Theory.

The basic premise of Constructor Theory is that all physical theories can be described in terms of which transformations of matter (events or tasks) are possible, which are impossible, and why. Constructor Theory refers to such transformations as “tasks”, because it considers potential, not yet occurred transformations. For the purpose of the current framework, we will refer to transformations as a “events”, because more often than not we will be interested in transformations that have already occurred. Each “event” consists of an input configuration of matter (which can be described by a finite set of physical variables), an output configuration of matter (ditto), and an agent (Mechanism/Constructor) which performs the task by generating the output when presented with the input. In Constructor Theory, the agent remains essentially unchanged and thus able to repeat the process. For purposes of the current framework, we will make the same assumption for events, because that constraint will hold for the events of interest.

An event is typically diagrammed thusly:

input state of substrate(s) ⎯⎯> [mechanism]⎯⎯> output state of substrate(s).

One can immediately see the resemblance to an information process (Input -> [processor] -> Output). What remains is to explain how concepts like information, meaning, knowledge, and experience can be tied to physical systems using this framework. Read on, oh lover of wisdom.